#ifndef SINGLETON_H
#define SINGLETON_H
#include"Global.h"
template <typename T>
class Singleton
{
protected:
    Singleton() = default;
    Singleton(const Singleton<T>&) = delete;
    Singleton& operator = (const Singleton<T>& st) = delete;
    static std::shared_ptr<T> _instance;
public:
    static std::shared_ptr<T> GetInstance()
    {
        static std::once_flag s_flag;
        std::call_once(s_flag,[&]()
        {
            _instance = std::shared_ptr<T>(new T);
        });
        return _instance;
    }
    void PrintAddress()
    {
        qDebug()<<_instance.get()<<'\n';
    }
    ~Singleton()
    {
        qDebug()<<"this is singleton destruct\n";
    }
};
template <typename T>
std::shared_ptr<T> Singleton<T>::_instance = nullptr;
#endif // SINGLETON_H
